Wheelchair Stair Assist Apparatus

ABSTRACT

An apparatus is disclosed for use on standard or customized wheelchairs for moving the wheelchair and wheelchair occupant up or down a stairway or stairway-like structure (e.g., a curb) with greater confidence and stability to the occupant of the wheelchair and its handler(s). The apparatus includes a motorized assembly that interacts with stair steps when the apparatus and wheelchair are tilted backwardly. The motorized assembly allows the wheelchair to glide or move up or down the steps without experiencing the bumps commonly associated with rolling a wheelchair up or down a set of stairs. The apparatus includes a headrest to provide comfort to the occupant during operation and includes pivoting handlebars to allow the operator of the wheelchair to control the movement of the wheelchair. The apparatus is mountable to, and removable from (when not in use), the wheelchair. The apparatus can be considered as a retrofit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/170,416 filed on Jun. 28, 2011, which is a continuation of U.S.patent application Ser. No. 11/857,789 filed on Sep. 19, 2007 (now U.S.Pat. No. 7,988,157), which is a nonprovisional of U.S. ProvisionalApplication No. 60/826,093 filed on Sep. 19, 2006, and claims thebenefit of each of the aforementioned applications, the entiredisclosures of which are incorporated by reference herein.

FIELD OF THE INVENTION

This invention relates in general to the field of medical devices andapparatus and in particular to a wheelchair stair assist apparatus forassisting the wheelchair and occupant thereof to ascend and/or descend astairway or stairway-like structure, such as a curb.

BACKGROUND OF THE INVENTION

Conventional wheelchairs have two large rear wheels rotatably mountedbeneath a vertical side frame member and two caster wheels mounted to arail or fork on the front of the wheelchair assembly. Conventionalwheelchairs as presently manufactured cannot provide for a safe and“bump free” use by an occupant of the wheelchair to ascend or descendstairways. In order for a standard design wheelchair to be used in thetransporting of an occupant up or down a stairway, the wheelchair mustbe tipped backward, with the occupant in it, by a handler or attendantof the wheelchair and then slowly lowered or raised, one step at a timeon the stairway. Safe practice generally requires that a secondattendant should grasp the front caster wheels or frame of thewheelchair and walk with the wheelchair as the occupant and wheelchairare raised or lowered on a stairway. Due to the size of the rear wheel,the wheelchair must be slowly lifted or lowered one stair at a time andin a manner that causes the occupant to be jolted or bumped as thewheels pass to the next step. This can, in extreme circumstances, leadto a total loss of control, resulting in a “free fall” situation for theoccupant and/or the handler. In other circumstances, this can lead toanxiety and severe discomfort, particularly to older occupants of thewheelchair as well as individuals and persons suffering from injury orother trauma. And this can cause damage to the wheelchair as well.Further, using the wheelchair to ascend or descend a stairway is timeconsuming and places the occupant and handler at risk of injury due tothe difficulty of a handler to control the wheelchair on the stairway,particularly on any stairway. Also, the handler must bend over thewheelchair at an uncomfortable angle when the wheelchair is tippedbackwards on the stairwell. This leads to an uncomfortable experiencefor the handler, who must ensure that the wheelchair is lifted up andoutward to clear a riser when ascending, as well as an increased risk tothe safety of the wheelchair occupant and the handler.

Many wheelchair-bound persons, due to the difficulty of ascending ordescending stairways and curbs, are prevented from gaining access tobuildings and to the upper levels of multi-story buildings. Not onlydoes this affect their mobility, but it also affects their ability togain employment since many employers do not want to cope with awheelchair-bound employee who cannot freely move from one floor toanother in a place of employment. Also, hospitals, nursing homes andother multi-story patient care facilities must rely on elevators to movewheelchair-bound patients from one floor to another due to thedifficulty of negotiating a stairway. Medical transport services thatoften transport sick, invalid, obese, or elderly patients havedifficulty in transporting such patients in a wheelchair. Extremedifficulties have been encountered in the patients' homes where thewheelchair-bound person must be raised and lowered along a narrowstairwell. In many cases this prevents such a person from utilizing hisor her whole house and forces him or her to live on only one floor of amulti-story dwelling.

Additionally, during a fire situation or other hazard when the elevatorsof most hospitals, nursing homes, and other multi-story buildings areshut down, residents are required to use stairways to exit the building.In so doing, particularly for wheelchair-bound invalids, there is a riskof injury, and great delay in removing them from the building in a safeand efficient manner. Such a delay also affects the ability of otherbuilding occupants to exit the building quickly and safely therebyincreasing the risk of an overall panic where people are needlesslyinjured or killed. Current fire escape plans for many of these buildingsinvolve placing a wheelchair-bound patient in a blanket and having fourpeople, each carrying a corner of the blanket, remove the patient fromthe building. This method depends on the availability of four peoplestrong enough to carry such a patient while ignoring the possible needfor life sustaining equipment to be carried along with the patient.Therefore, the current state of emergency exit plans for most nursinghomes and hospitals expose many of the wheelchair-bound and invalidpatients to extreme danger in a fire situation.

Attempts have been made in the past to provide a means for ascending ordescending stairs in a wheelchair in a manner that would not place theoccupant at any risk of harm or jolt the occupant as the wheelchair israised or lowered up the stairs. For example, some options includeattaching a device to a standard wheelchair where: a) the device ispermanently attached; b) the device is heavy and/or cumbersome tomanufacture; and/or c) the device is expensive to own. Some otheroptions provide for a special wheelchair equipped forascending/descending stairs. Such wheelchairs are usually expensive tomanufacture and conventional wheelchairs have to be replaced by suchspecialized wheelchairs to be able to take advantage of the stairwayascending/descending feature. Yet other options restrict the movement ofthe wheelchair both when the apparatus is in use and not in use.Frequently, all the above-indicated options require manualhandling/control of the wheelchair by a handler to assist in moving thewheelchair up and/or down the stairs.

As is already evident, most conventional options for wheelchairs inassisting movement up or down a set of stairs have numerousdisadvantages and problems. It would, therefore, be advantageous if anapparatus is developed, that while overcoming some, or all of thedisadvantages and risks of the conventional options, also providesadditional advantages. For example, instead of having the handlercontrol the rate of ascent/descent, an apparatus that includes amotorized mechanism to move the wheelchair and occupant up and down thestairs would be beneficial. It would further be advantageous to providea lightweight, easily-manufactured and affordable wheelchair apparatuscapable of fitting to a wheelchair of a standard design for providing asafe and smooth means by which the wheelchair and occupant thereof canbe raised or lowered on the stairway.

It would additionally be advantageous if an apparatus that is removablyaffixed to the wheelchair such that the apparatus can be removed fromthe wheelchair and conveniently stored if desired is developed. Such anapparatus would further provide an independent means of control notdirectly linked to the wheelchair handlebars for avoiding interferencewith the operation of the chair both when the apparatus is in use andnot in use. Further, attaching such an apparatus to a wheelchair (or anyother chair) would not interfere with the normal functioning of thewheelchair, allowing the wheelchair to function just as it would withoutthe apparatus attached.

SUMMARY OF THE INVENTION

The present invention is directed to a wheelchair apparatus that may beassembled on a new wheelchair or a conventional wheelchair that ispresently or has been previously manufactured. Additionally, the presentinvention can be attached to any other type of a chair, with or withoutwheels, for moving the chair and occupant thereof up and/or down stairs.The present invention entails a minimum of modifications, or possiblyeven no modifications, to the standard chair and as such may be addedeither as a kit to an existing wheelchair that has already beenpurchased by a user, or may be added as an accessory by a manufacturerof wheelchairs.

The subject invention meets the objects as expressed herein as theapparatus is easily attachable and detachable to a standard wheelchairwith a minimum of modification, or possibly even no modifications, tothe chair. Further, when properly used, the subject invention provides ameans by which a wheelchair-bound person may be raised or lowered alonga stairway with greater confidence and in an efficient manner. Further,the subject invention does not restrict the normal movement of the chairwhen the device is either in use or not in use. Additionally, theapparatus can easily be removed for collapsing the wheelchair forstorage. The subject invention provides a means by which an occupant ofthe chair may be raised or lowered on a stairway without suffering the“jolts” or “bumps”, or risks, commonly experienced with the presentmethods of raising or lowering a person on a stairway.

This invention provides an apparatus for assisting a wheelchair and anoccupant thereof to ascend or descend a stairway or stairway-likestructure. To this end the apparatus comprises a housing that issecurable to a wheelchair. In addition, a motorized assembly securablewithin or substantially within the housing is provided for automaticallymoving the wheelchair up or down the stairway or stairway-likestructure. Also provided is an attachment mechanism for securing thehousing and the motorized assembly to the wheelchair, thereby preventingthe apparatus from separating from the wheelchair. Other features,objects, and advantages of the present invention, in its variousembodiments, will become apparent upon a reading and review of thedetailed description, including the claims, and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Features of the present invention which are believed to be novel are setforth with particularity in the appended claims. Embodiments of theinvention are disclosed with reference to the accompanying drawings andthese embodiments are provided for illustrative purposes only. Theinvention is not limited in its application to the details ofconstruction or the arrangement of the components illustrated in thedrawings. Rather, the invention is capable of other embodiments and/orof being practiced or carried out in other various ways. The drawingsillustrate a best mode presently contemplated for carrying out theinvention. Like reference numerals are used to indicate like components.In the drawings:

FIG. 1 is a side view of the improved wheelchair apparatus used to movea wheelchair and occupant up and down stairs and curbs;

FIG. 2 illustrates the apparatus secured to the wheelchair having anoccupant and raising or lowering the wheelchair up or down stairs;

FIG. 3 is a rear perspective view of the apparatus partially showing theinternal mechanisms of the apparatus;

FIG. 4 is a rear perspective view of the apparatus illustrating theremoval of a detachable assembly;

FIG. 5 is a side view of the apparatus attached to the wheelchair havingan occupant, and the wheelchair being operated by a user moving theapparatus to engage stairs;

FIG. 6 is a front perspective view of the apparatus;

FIGS. 7 a and 7 b are front perspective views of mechanisms used tosecure the apparatus to the wheelchair.

FIG. 8 is a rear perspective view of an apparatus secured to awheelchair in accordance with at least some alternate embodiments of theinvention, partially illustrating some internal mechanisms of theapparatus;

FIG. 9 is a rear perspective view of the apparatus of FIG. 8illustrating a detachable assembly in accordance with at least someembodiments of the invention;

FIG. 10 is an exploded view of the detachable assembly of FIG. 9 showingvarious assemblies and sub-assemblies of the apparatus connectedtogether in operational association in accordance with at least someembodiments of the invention;

FIG. 11 is a front perspective view of an exemplary frame member (asshown, a left frame member) of the apparatus in accordance with at leastsome embodiments of the invention;

FIG. 12 is a front perspective view of another exemplary frame member(as shown, a right frame member) of the apparatus in accordance with atleast some embodiments of the invention;

FIG. 13 is a front perspective view of an exemplary motor assembly foruse with the apparatus in accordance with at least some embodiments ofthe invention;

FIG. 14 is a front perspective view of an exemplary drive axle assemblyof the apparatus in accordance with at least some embodiments of theinvention;

FIG. 15 is a front perspective view of an exemplary roller assembly ofthe apparatus in accordance with at least some embodiments of theinvention;

FIG. 16 is a front perspective view of an exemplary idler shaft assemblyof the apparatus in accordance with at least some embodiments of theinvention;

FIGS. 17A-B are side perspective and exploded side perspective views,respectively, of an exemplary top chair attachment assembly of theapparatus in accordance with at least some embodiments of the invention;

FIGS. 18A-B are side perspective and exploded side perspective views,respectively, of an exemplary bottom chair attachment assembly of theapparatus in accordance with at least some embodiments of the invention.

FIG. 19 is a front perspective view of an exemplary assist assembly ofthe apparatus in accordance with at least some embodiments of theinvention;

FIG. 20 is a side perspective view of an exemplary handle bar assemblyof the apparatus in accordance with at least some embodiments of theinvention;

FIG. 21 is a front perspective view of an exemplary headrest assembly ofthe apparatus in accordance with at least some embodiments of theinvention;

DETAILED DESCRIPTION

The invention described herein can be implemented on wheelchairs ofvarious types. For purposes of clarity and simplicity, and for teachingpurposes, and not by way of limitation, the invention is shown anddescribed as applied to a standard type wheelchair as shown in FIG. 1.As illustrated in FIG. 1, the standard wheelchair, generally referencedby numeral 10, has front caster wheels 12 connected to front forks 14which forms a part of wheelchair arms 16. Also connected to front forks14 are the footrest assemblies 18. The rear side frame 20 of the chair10 has front rail 22 connected to the vertical member of side frame 20.Large rear wheels 24 are rotatably connected at axle 26 to the rear sideframe 20. Large rear wheels 24 have hand rail 28 connected thereto byvirtue of a series of spacers and clips 30 and spokes 25 mounted betweenwheel 24 and axle 26. The spacers provide the necessary distance betweenrear wheel 24 and hand rail 28 so that an occupant of the chair canself-motivate himself by using the handrail to roll the large rearwheels 24 of chair 10. Arm rests 16 may or may not be removabledepending on the type and manufacture of the chair 10. Also formed alongside rear side frame 20 are handlebars 32. These handlebars 32 arenormally what an attendant or handler of the chair 10 would grip toassist an occupant of the chair 10 in moving the chair 10 from one placeto another.

The present invention is shown in FIG. 1 and is shown attached to thechair 10 in FIG. 2. The invention comprises an apparatus 50 thatincludes a motorized track assembly 60 that automatically moves thewheelchair 10 up or down stairs. The apparatus 50 mounts to the rearportion 34 of the wheelchair 10 by locking onto clamping pins 52 thatare secured to the wheelchair 10 (explained in greater detail below).

Illustrated in FIG. 2 the apparatus 50 is secured to the wheelchair 10and is adjacent to a stairwell 40. The motorized track assembly 60 isillustrated engaging the stair steps 42 of the stair well 40 such thatthe approximate length of the motorized track assembly 60 is shown withrespect to the individual stair steps 42.

FIGS. 3 and 4 illustrate the back view of the apparatus 50. Themotorized track assembly 60 is secured within a housing 54 defined bythe apparatus 50. The motorized track assembly 60 is controlled by amotorized drive 62 that rotates a pair of lower track wheels 64. A pairof upper track wheels 66 is freely rotatably attached inside the housing54. Over the rollers is placed a tread 68 such that the tread is able tomove in a continuous motion around the wheels as the wheelchair 10 israised or lowered along a stairway 40. The tread 68 is comprised of agrooved rubber-like material for traction and gripping the stairway 40.This allows the motorized track assembly 60 to rest on two outer edgesof the stair steps 42 at a time and thus prevents the bumping of therear wheel 24 as the wheelchair 10 is raised or lowered along thestairway. The apparatus 50, when attached to the wheelchair 10 the outeredge of the tread 68, is approximately tangent to the rear wheel 24 sothat the tread 68 will engage the stair steps 42 as the wheelchair 10 israised or lowered along the stairway. By “approximately tangent to therear wheel 24,” it is meant that the outer edge of the tread 68 lines upwith the outer edge of the rear wheel 24 as shown in FIG. 2.

The apparatus 50 includes a detachable assembly 70, that stores thebattery pack 72 and control mechanism (not shown) as well as includes aheadrest 74 and pivoting handle bars 76. The detachable assembly 70 iseasily removed and attached to the apparatus 50 with the use of aplurality of locking mechanisms 78 (well known in the art) positioned onboth sides, the top portion and the front portion of the detachableassembly 70. The battery pack 72 disconnects from the motorized drive byuncoupling an electrical connector 79, shown below the battery pack 72on FIG. 4. Alternatively, a removable battery pack 72 capable of beingattached to the detachable assembly 70 can be used.

Referring now to FIG. 5, it is shown that the apparatus 50 does notinterfere with the wheelchair 10 when it is attached thereto. Asillustrated throughout the Figures, the handlebars 76 which an operatorof the apparatus may grasp during use are adjustable and pivotable.Referring to FIG. 4 in conjunction with FIG. 5, the handlebars 76 aresecured to a top portion 56 of the housing 50. The handlebars 76 consistof a first pair of bars 80 that extend through slots 82 mounted on topportion 56 of the housing 50. Various notches 84 positioned on the firstpair of bars 80 permit the first pair of bars 80 to be lowered or raisedto a desired height. Secured across the first pair of bars 80 is a crossbar 86 to which the adjustable headrest 74 is attached. The first pairof bars 80 is connected via a pivotal connection 88 to a second pair ofbars 90. The pivotal connection 88 may consist of two interlockingdetent plates that when the two plates are loosened the second pair ofbars 90 may be pivoted to a desired location. The second pair of bars 90are hollowed to receive a third pair of bars 92 that includes a handle94 secured transversely across the end of the third pair of bars 92. Thethird pair of bars 92 includes notches (not shown) for locking the thirdpair of bars 92 in at a desired height (FIG. 2) with locking pins 97.The locking pins 97 may be spring-loaded pins that are biased inwardlythrough the second pair of bars 90 to engage the notches of the thirdpair of bars 92.

Referring now to FIG. 6, the front of the apparatus is illustrated. Asshown, the apparatus may be turned on and operated using a switch 98located on the handle 94. Preferably, the switch 98 toggles thedirection of the apparatus and the movement of the tread 68. When theswitch 98 is moved to the “up” position, the tread 68 is capable ofmoving the apparatus, and therefore the wheelchair to which it isattached, up the stairs. Alternatively, when the switch 98 is moved tothe “down” position, the tread 68 is similarly capable of moving thewheelchair 10 down the stairs. To prevent the apparatus 50 from movingthe wheel chair 10 unattended by the user, as soon as the user releasesthe switch 98, the switch toggles back to a neutral center position andthe apparatus is automatically switched off. Also illustrated moreclearly in FIG. 6 are the means through which the apparatus 50 issecured to the wheelchair 10. The apparatus 50 includes a rotating bar100 that is secured through a pair of plates 102 that suspend therotating bar 100 away from the front portion 103 of the apparatus 50.

With reference to FIGS. 2, 7A and 7B, fastened to both ends of therotating bar 100 are end caps 104 that include U-shaped notches 106,which engage pins 122 on first pair of clamping pins 52. Similarly, thelower front portion of the apparatus includes U-shaped notches 110 thatalso engage pins 122 on a second set of clamping pins 52. To lock theapparatus 50 against the wheelchair 10, the four clamping pins 52,including the first and the second sets, are engaged and the operatorrotates a crank handle 108 that is attached to the rotating bar 100. Thecrank handle 108 rotates the U-shaped notches 106 on the end caps 104 ofthe rotating bar 100 away from the wheelchair 10, such that theapparatus 50 is secured to the wheelchair 10, preventing the apparatusfrom accidentally disengaging. The clamping pins 52 include pins 122 forengagement by the apparatus 50. The clamping pins 52 also include anaperture 124 formed when two pieces 126 and 128 defined by the clampingpins are assembled. The aperture 124 is sized to receive either thefront rail 22 or the rear side frame 20 of the wheelchair 10. To furthersecure the apparatus 50 to the wheelchair 10, the apparatus 50 caninclude straps (not shown) that secure around the wheelchair'shandlebars 32 as metal clips and/or plates 126.

Referring now to FIGS. 8-21, exemplary features and associatedcomponents of an apparatus 190 (also referred herein as a stair assistapparatus or a wheelchair apparatus) are shown in accordance with atleast some alternate embodiments of the present invention. Inparticular, FIG. 8 is a rear perspective view of the apparatus 190secured to a wheelchair 192. FIG. 8 also partially illustrates variousinternal features of the apparatus 190. FIGS. 9 and 10 illustratevarious assemblies and sub-assemblies of the apparatus 190 connectedtogether in operational association with one another and each of theFIGS. 11-21 present views of a number of assemblies, including a bodyassembly 225, an assist assembly 202, a handlebar assembly 207 and aheadrest assembly 209, as well as sub-assemblies of the apparatus 190.Each of the figures is described in greater detail below. The apparatus190 is contemplated for use in conjunction with a wide variety ofwheelchairs, as previously mentioned, that are commonly available andfrequently used. As shown in FIG. 8, the apparatus 190 is attached tothe rear portion of the wheelchair 192 by way of attachments/mechanismsdescribed later in the application. While the apparatus 190 is shownattached or otherwise connected to the wheelchair 192, it can beunderstood that the apparatus is easily detachable from the wheelchair.Such detachability is an advantageous aspect of the present invention.For example, by virtue of being detachable, the apparatus 190 can beeasily removed from one wheelchair and attached with another. Also, thedetachability aspect is beneficial insofar that the apparatus 190 can beeasily and conveniently transported from one location to another.Efficient storage is an added bonus. Accordingly, in at least some otherembodiments of the present invention, the apparatus can be considered orused as a retrofit.

Referring to FIGS. 9 and 10, which are rear perspective and explodedviews of the apparatus 190, respectively, are shown in accordance withat least some embodiments of the present invention. As shown, thevarious assemblies (e.g., the body assembly 225, the assist assembly202, the handlebar assembly 207 and the headrest assembly 209),sub-assemblies and components thereof, including a wide variety ofelectrical and mechanical parts held together in operationalassociation, can be seen in greater detail in FIG. 10. The assembliesare generally contained within a housing 227. The housing 227 furtherincludes a top cover 211, a bottom cover 212. Abutting the housing andmore specifically, the top and the bottom covers 211 and 212respectively of the housing are left and right frame members 204 and205, respectively. The respective left and the right frame members 204and 205, described further below, are used for securing the variousassemblies in position within the housing 227.

Turning now to FIGS. 11 and 12, exemplary left and right frame members204 and 205, respectively are shown in accordance with at least someembodiments of the present invention. The size and shape of each of theleft and the right frame members mirror each other and at least in thisfashion, the frame members are substantially similar. In particular, asshown in FIG. 11, the left frame member 204 includes a main frame 204Adefining a number of protrusions and depressions in various shapes andsizes (all of which are not numbered separately) for securing inposition the various assemblies of the apparatus 190 and/or componentsthereof. Also connected to the main frame 204A is a belt guide 204B forrotatably mounting and guiding a motorized belt 215 for transporting thewheelchair 192 and an occupant thereof up and/or down stairs. A beltadjustment block 204C for adjusting the alignment of the belt 215 alongthe belt guide 204B during operation is also provided on the main frame204A. Similarly, as shown in FIG. 12, the right side frame 205 includesa main frame 205A, a belt guide 205B and a belt adjustment block 205Caccomplishing the same, or at least substantially similar, functions asthe components of the left frame member 204.

Turning back to FIGS. 9 and 10, the motorized belt 215 having aplurality of continuous treads further includes first and second belts,referenced generally by the reference numeral 215 (see FIG. 10), mountedon the respective left and the right frames 204 and 205. The motorizedbelts 215 can be any of a wide variety of belts that are known, however,in general, the motorized belts 215 will provide traction on the stairsduring operation. For example, in accordance with at least someembodiments, the motorized belts 215 can comprise rubber belts, and inat least some preferred embodiments, optimal durometer rubber belts canbe used. Additionally, a “no mark” rubber can be used to prevent themotorized belt 215 from leaving tread marks on the stairs.

The rotational movement of the motorized belts 215 to accomplish travelup and down a stairwell is provided by a drive assembly 229 (see FIG.10) connected at least indirectly to the motorized belts. The driveassembly 229 further includes various sub-assemblies. The sub-assembliesinclude: an electrical box 218 for serving as an end or transition pointfor a variety of electrical wires within the apparatus 190; a batterypack 217 including first and second batteries 217A and 217B,respectively, mounted in respective battery support brackets 213 and213A; a drive axle assembly 200; a motor assembly 206; and an idlershaft assembly 201. With respect to the battery pack 217, each of therespective first and the second batteries 217A and 217B within thebattery pack can be re-chargeable or replaceable batteries that aremounted to the respective left and the right frame members 204 and 205through the battery support brackets 213 and 213A, respectively. Forexample, in the present embodiment each of the first and the secondbatteries 217A and 217B, respectively, can include two 12 voltbatteries. Nonetheless, in other embodiments, other arrangements andconfigurations can be used. To provide additional support and restrictmovement of the batteries within the battery mounting bracket, aplurality of straps for securing the batteries to the frame members canbe used.

Referring now to FIG. 13, an exemplary motor assembly 206 for use indriving the drive axle assembly 200 is shown. The motor assembly 206, inparticular, is connected at least indirectly to the battery pack 217 andincludes a drive motor 206C. The assembly further includes first, secondand third motor brackets 206A1, 206A2 and 206A3, respectively, formounting the drive motor within the motor assembly as well as agear-head 206B and a precision roller chain sprocket 206D for convertingelectrical energy from the drive motor to mechanical energy for drivingthe drive axle assembly 200. In general, a wide variety of gear-headsand sprockets, other than those specifically mentioned above can be usedin the present invention. Similarly, the drive motor 206C can be any ofa wide variety of electric or electromechanical motors that are known.Additionally, the drive motor 206C can comprise a dual-direction motorcapable of moving the apparatus 190 in a wide variety of directionsincluding, for example, up or down a stairwell, or possibly evenstopping the apparatus (by virtue of a brake mechanism present in themotor) in a particular position. The motor assembly 206 is mounted toeither the left or the right frame members 204 and 205, respectively,via one or more of the motor brackets 206A1-206A3 and the actuation ofthe drive motor 206C is achieved by way of buttons/switches present onthe handlebar assembly 207, described later in the application (FIG.20).

Turning now to FIG. 14, an exemplary drive axle assembly 200 is shown inaccordance with at least some embodiments of the present invention. Asshown, the drive axle assembly 200 includes: a drive shaft 200Asupported on both sides by timing belt pulley mechanisms 200B over whichthe motorized belts 215 are freely mountable for rotation; a drive gear200C for rotating the shaft and hence, the timing belt pulley mechanisms200B; and bushing 200D for reducing wear and tear between the variousparts of the drive axle assembly 200. The gear, pulley mechanisms andthe bushing can be any of a wide variety of those that are commonlyavailable. For example, an exemplary bushing can comprise OILITE®bushings, available from the McMaster supply company, although othertypes of bushings are contemplated. The drive gear 200C has mountedthereon a drive chain 214 the other end of which is connected to themotor assembly 206 for providing rotational motion to the drive shaft200A and the timing belt pulley mechanisms 200B. By virtue of therotation of the timing belt pulleys, the motorized belts 215 can berotated. Additionally, the timing belt pulley mechanisms 200B andtherefore the motorized belts 215 are capable of rotating in bothclockwise and counterclockwise directions. In this fashion, as themotorized belts 215 are rotated, the wheelchair to which the stairassist apparatus is attached can be carried up and/or down the stairs ofa stairwell.

Turning to FIG. 15, an exemplary roller assembly 203 is shown inaccordance with at least some embodiments of the present invention. Theroller assembly 203 is attached/connected to the drive axle assembly 200previously described and the roller assembly 203 provides additionalsupport to maintain the apparatus 190 in an upright position (See FIG.8) when the apparatus is laid on a flat surface. As shown, the rollerassembly 203 includes a set of assist wheels 203B separated by a shaft203A and held in position by retaining rings 203C. The size of theassist wheels can vary from one embodiment to another. For example, inthe present embodiment, a diameter of 3.25 inches is used for each ofthe wheels 203B. The wheels 203B assist the apparatus in beingtransported easily from one point to another in an easy and convenientfashion.

Referring to FIG. 16, the apparatus 190 (FIG. 8) further includes anidler shaft assembly 201, an exemplary embodiment of which is shown, formaintaining proper alignment and orientation of the drive axle assembly200. As shown, the idler shaft assembly 201 includes a pair of timingbelt pulley mechanisms 201B mounted on an idler pulley shaft 201A. Thepulley mechanisms 201B are retained in position, and protected to atleast some extent from wear and tear, by way of two sets of bushings201C, with one bushing being mounted on either side of a respectivetiming belt pulley mechanism.

Turning back to FIGS. 9, 10, the headrest assembly 209, the handlebarassembly 207, and the drive axle assembly 200 are secured to the leftand the right frame members 204 and 205 respectively, by way of aplurality of connecting rods. More specifically, connection isaccomplished by smaller first, second and third connecting rods (notspecifically numbered), and a larger connecting rod 219. The idler shaftassembly 201, the motor assembly 206 and the battery pack 217 are allalso mounted to the left and/or the right frames 204 and 205 by way ofmounting brackets, or other fastening means or mechanisms includingscrews, nuts and bolts. In addition, it is possible that a wide varietyof adhesives can be used.

The aforementioned assemblies and sub-assemblies that are mounted to oneor more of the respective left and right frame members 204 and 205 aresecured to the apparatus housing. The apparatus 190 in turn is attachedto the wheelchair 192 by virtue of top and bottom chair attachmentassemblies 208 and 210, respectively, described below. Turning now toFIG. 17A-B, an exemplary top chair attachment assembly 208 is shown inaccordance with at least some embodiments of the present invention. Asshown in FIG. 17A-B, the top chair attachment assembly 208 includes achair attachment tube 208A mounted adjacent to the handlebar assembly207. Attachment mechanisms 208′ and 208″, which are identical orsubstantially similar, are provided on both ends of the chair attachmenttube 208A. For simplicity of description, the attachment mechanism onone side (the right side 208″) of the chair attachment tube 208A isdescribed. As shown, a guide tube 208C2 is mounted in mating alignmentwith and separated by the chair attachment tube 208A by a male disc208C1. The male disc 208C1 has a plurality of teeth that are capable ofengaging the main frame of the wheelchair 192. Also provided is a widthadjuster tube 208B2 having a plurality of notches on its surface. Thewidth adjuster tube 208B2 is capable of rotating and sliding in and outof the guide tube 208C2. Rotation is locked when the disc teeth of themale disc 208C1 engage with the main frame. One or more pins (notseparately numbered), by virtue of engaging with one or more of thenotches (not separately numbered) on the surface of the width adjustertube 208B2, prevents further sliding motion of the width adjuster tube.Additionally, the width adjuster tube 208B2 is provided by a tube stop208B3 on the end facing the guide tube 208C2 and a guide rod 208B1 onthe opposite end. The tube stop 208B3 provides frictional engagementwithin the guide tube 208C2.

Still referring to FIG. 17A-B, the guide rod 208B1 is capable of slidingin and out of a height adjuster tube 208B4 for adjusting the height ofthe apparatus 190 when attached to the wheelchair 192. Similar to thewidth adjuster tube 208B2, the height adjuster tube 208B4 has aplurality of notches on its surface and tube stop 208B11 on one end. Theheight adjuster tube is capable of sliding in and out of the guide road208B1 and being locked by a mechanism, described below, that engages oneor more of the notches on the surface of the height adjuster tube 208B4.

Also provided is another attachment tube 208B10 secured to the heightadjuster tube 208B4 in the manner shown in FIG. 17A-B. The attachmenttube 208B10 has mounted thereon a rubber grip 208B5 for providing acomfortable grip for rotating the width adjuster tube 208B2. Beneath therubber grip 208B5 is located a CAM disc 208B8 that is attached on oneend to the height adjuster mechanism 208B4 and the other end isrestrained by way of a flat washer 208B8 and retaining ring 208B9. TheCAM disc 208B8 primarily provides a locking mechanism for the heightadjuster mechanism 208B4. Notwithstanding, that in the presentembodiment components described above have been used, it is neverthelessan intention of this invention to include embodiments, in whichalternative mechanisms including, other attachment or engagement meansand/or fasteners, capable of providing similar or substantially similarfunctionality as the components described above, can be used.

Turning now to FIG. 18A-B, an exemplary top chair attachment assembly210 is shown in at least some embodiments of the present invention. Ascan be seen, the bottom chair attachment 210 is similar to the top chairattachment 208 having similar components. Also, the left and the rightportions 210′ and 210″, respectively, of the bottom chair attachment areidentical or at least substantially similar. However, an extra pivot,for allowing height variations between different types of wheelchairmakes and models is provided in the bottom chair attachment 210. Asshown, the bottom chair attachment 210 includes a chair attachment tube210A. With attention to the right side portion of the chair attachmenttube 210A, a male disc 210C1 and a guide tube 210C2 are shown. Further,a width adjuster tube 210B1 having a plurality of notches, a tube stop210B2 on one end and a guide rod 210B3 on the other end of the widthadjuster tube, is provided. The width adjuster tube 210B1, as previouslymentioned, is capable of rotating and sliding in and out of the guidetube 210C2 until the male disc 210C1 engages with the main frame of thewheelchair 192. Subsequently, a locking mechanism, such as a pin, canlock the width adjuster tube 210B1 in position.

The guide rod 210B3 is pivotable about the width adjuster tube 210B1 andserves to adjust the height of the apparatus 190 by way of a heightadjuster tube 210B4. The height adjuster tube 210B4 has a plurality ofnotches on its surface and a tube stop 210B5 on one end. Also attachedto the height adjuster tube 210B4 is another attachment tube 210B03 towhich a metal swivel plate 210B61 is mounted. A rubber grip 210B62 forproviding a comfortable grip during rotating the width adjuster tube210B1 is provided on the metal swivel plate 210B61. A CAM disc 210B65attached to the metal swivel plate 210B61 by way of a rod 210B64, ane-clip 210B67 and a flat washer 210B66 is provided for adjusting theheight of the height adjuster tube. Notwithstanding the previouslymentioned components of the bottom chair attachment that are used in thepresent embodiment, it is nevertheless an intention of this invention toinclude embodiments, in which alternative mechanisms including, otherattachment or engagement means and/or fasteners, capable of providingsimilar or substantially similar functionality as the componentsdescribed above, can be used.

Referring now to FIG. 19, a rear perspective view of an exemplary assistassembly 202 is shown in accordance with at least some embodiments ofthe present invention. The assist assembly 202 serves a variety ofdifferent purposes. To begin with, the assist assembly 202 can be usedto lower the apparatus 190 and/or the wheelchair 192 (having anoccupant) to an appropriate angle of the stairs (or any angle that thehandler of the wheelchair deems appropriate) for supporting the weightof the apparatus, the wheelchair and the occupant thereof. Such asupport mechanism releases the burden off the handler as the handler nolonger has to support the occupant to prevent the occupant from fallingoff. Further, the assist assembly 202 provides support to the wheelchairand the occupant thereof as the apparatus 190 is raised at a verticalangle at the top of the stairs (or at the bottom of the stairs).Additionally, the assist assembly 202 can be used as a “tri-pod” intandem with the assist wheels 203B of the roller assembly (describedabove in regards with FIG. 15) to transport the apparatus 190 to thewheelchair 192 for ease of installation or alternatively from thewheelchair to a storage location.

The assist assembly is generally secured in a stored position in adepression made on the bottom cover 212 (FIG. 10), being actuated to aworking position generally during operation of the apparatus 190. Theactuation of the assist assembly 202 can be facilitated by way ofmechanisms located on the handlebar assembly 207, described below,allowing for a convenient transformation from the stored position to theworking position and vice-versa. In particular, the assist assembly 202includes a first main ratchet or winch system 221 and a secondarysmaller ratchet or winch system 222 (See FIG. 10) for controlling theassist assembly during translation from the stored to the workingposition and vice-versa on actuation of the handlebar assembly 207.Further, the assist assembly 202 can be activated by virtue of the mainand the secondary ratchet systems 221 and 222, respectively, at any time(and at any angle) by actuating the handlebar assembly 207. In alternateembodiments, it is contemplated that the number, size and/or type of theratchet and/or winch system(s) can vary to convenience. Additionally, inalternate embodiments, it is contemplated that fiber-optic, infraredand/or direct wiring can be used to accomplish manipulation of theassist assembly 202 by activating a motor for moving the assist assemblyfrom a stored position to a working position and vice-versa.

As shown in FIG. 19, the assist assembly 202 includes a rod 202E, a pairof support bars 202B, a pair of wheels 202D and an assist rod 202A. Therod 202E in particular is used to attach the assist assembly 202 to thebottom cover 212 of the apparatus 190, for example, by a wide variety offastening, clamping, snapping and/or other engagement means. Theopposing ends of the support bars 202B are secured (potentiallyequidistant from the ends of the rod 202E) to the rod 202E and to theassist rod 202A. The support bars 202B are additionally capable ofpivotal motion about the rod 202E. By virtue of such a pivotal motion,with the aid of the ratchet systems 221 and 222, the support bars 202Ballow the wheels 202D to transform from the stored position to theworking position (See FIG. 9) and vice-versa. Additionally, the supportbars 202B are shaped appropriately with a slight curvature to providestability to the apparatus 190 while bearing the weight of the apparatusduring operation.

Further, the assist rod 202A is attached on both sides to the wheels202D that in particular are held in position on the assist rod by way ofa pair of retaining ring mechanisms 202F and a pair of bearingmechanisms 202C (e.g., bronze bearings). In other embodiments, otherretaining means including bolts, fastening clips, etc., can be used, andthe size of the wheel can vary in different embodiments. For example, inthe present embodiment, wheels having a diameter of 3.25 inches areused. Nonetheless, in other embodiments wheels of different sizesdepending upon the type of wheelchair can be used in conjunction withthe apparatus 190.

Referring now to FIG. 20 a side perspective view of an exemplaryhandlebar assembly 207 is shown in accordance with at least someembodiments of the present invention. The handlebar assembly 207 is usedfor manipulating the apparatus 190 up and down stairs (either alone orwith the wheelchair) as well as for controlling the motor assembly 206and the assist assembly 202. The handlebar assembly is secured to theleft and the right frame members 204 and 205, respectively, by way ofthe smaller connecting rods, which are held in place by a pair of pipebrackets 207R. Further, the handlebar assembly 207 includes a handlebarframe 207A that includes a generally U-shaped channel or channel portion207A1 with abutting side walls 207A2 and 207A3. A telescoping tube 207Dslides into (or out of) the handlebar frame 207A, and this motion isrestricted or constrained by a stop plate 207T, which is located, asshown, on one end of the handlebar frame. As such, the tube 207D can becharacterized as a telescoping, and adjustable and/or pivotable andcapable of telescopic movement for navigating and manipulating theapparatus 190. To ensure length adjustability, the handlebar assembly207 is first extended from its stored position within the left and theright frame members, 204 and 205, respectively, to achieve thetelescopic movement of the telescoping tube 207D.

Additionally, there exists on the handlebar frame 207A a quick releasemechanism (such as a quick pin) 207Q that releases the telescoping tube207D from a stored position enabling the telescoping tube to be pulledup into a working position. As the telescoping tube 207D is pulled outof the handlebar frame 207A, the telescoping tube is constrained fromfalling off from the handlebar frame by virtue of the quick releasemechanism 207Q. The quick release mechanism 207Q further serves toengage the third rod portion 207C, or alternatively the middle rodportion 207D1 (e.g., by way of micro adjustments present on the surface)securely in position during the manipulation or transportation of theapparatus 190. Notwithstanding the fact that in the present embodiment aquick release mechanism is used to engage the telescoping tube 207D tothe handlebar frame 207A, in other embodiments other clamping orconnecting means or mechanisms including plugs, nuts, screws, airpistons etc., can be used.

For achieving the telescopic movement, the telescoping tube 207D isfurther divided into multiple sub-portions including a first rod portion207G, a middle rod portion 207D1 and a third rod portion 207C that isconnected to the middle rod portion by an outer pipe 207F. Inparticular, the telescoping movement is achieved by virtue of the outerpipe 207F, which is defined by a plug and/or hinge 207E and/or allowsthe middle rod portion 207D1 to pivot about the outer pipe for maximumflexibility in navigating the apparatus 190. Advantageously, the middlerod portion 207D1 can be pivoted in either longitudinal direction or ina latitudinal direction. The longitudinal direction of movement includesmotion from a completely retracted position that is perpendicular to thethird rod portion 207C to a position that is in axial alignment) (180°)with the third rod portion. Alternatively, a latitudinal direction ofmovement can be achieved by pivoting the middle rod portion in anangular orientation to the third rod portion. The telescopic position ofthe telescoping tube 207D is dependent upon the position of theapparatus 190 on the stairs. Although an outer pipe is used to connectthe middle rod portion 207D to the third rod portion 207C in the presentembodiment, other fastening or connecting means and/or mechanisms thatprovide for pivotal movement are contemplated.

Still referring to FIG. 20, the middle rod portion 207D1 is a hollowtube into which the first rod portion 207A can slide for easy storage.To this end, the first rod portion 207A has a plurality of protrusions(or holes) each of which can be frictionally engaged by one or moreholding tabs 207S and handle bar stops 20711 present on the middle rodportion 207D1. Therefore, by virtue of the first rod portion 207G beingcapable of sliding in/out of the middle rod portion 207D1 and the middlerod portion being capable of sliding in/out of the handlebar frame 207A,the telescoping tube 207D can be conveniently stored duringnon-operation of the apparatus 190. Such a storage mechanism furtherprevents any damage to the telescoping tube 207D.

Generally, in the present embodiment, each of the rod portions 207G,207D1 and 207C, respectively, are hollow, substantiallyrectangularly-shaped rods, that provide for an apparatus that islight-weight (and yet strong) and easy to handle. Nevertheless, in otherembodiments one or more of the first, middle and third rod portions207G, 207D1 and 207C, respectively, can take the form of solid rods withthe rod portions folding with respect to one another. Additionally, eachof the rod portions can be made of a wide variety of materialsincluding, for example, plastic, metal, or other rigid or semi-rigidmaterial. Also, one or more of the rods can be of shapes other thanrectangular including, for example, cylindrical and hexagonal or thelike.

The middle rod portion 207D1 of the telescoping tube 207D includesbushings (e.g, nylon bushings) that are pressed or otherwise securedthereon to protect or substantially protect the telescoping tube fromdirt and damage. Additionally, such bushings provide a smoothtelescoping operation in the various directions. Additionally, the edgeof the third rod portion 207C is protected by a cap 2071 (e.g. a nyloncap). The presence of the cap 2071 prevents or substantially preventsany dust, debris or other particles from entering and blocking thetelescoping tube 207D and protect a user from any exposed sharp edges.Additionally, the edges of the outerpipe 207F (within the middle and thethird rod portions) can be covered by a cap 207J (e.g., a nylon cap).Although a nylon cap is disclosed and used in the present embodiment,other covers and/or caps of other types and/or made of other materialsincluding plastic, metal or other rigid and semi-rigid material canpotentially be used in other embodiments.

Still referring to FIG. 20, in addition to the various portions of thetelescoping tube 207D that afford flexibility and navigationalconvenience, the handlebar assembly 207 is also equipped with ahandlebar 207K that enables manipulation of the apparatus 190. Inalternate embodiments, the manipulative capabilities of the handlebar207K can be accomplished fiber-optic, infra-red, or direct wiring. Asshown, the handlebar 207K includes a pair of opposing handlebar grips207L for grasping the handlebar 207K for convenient navigationalfacility. Each of the handlebar grips 207L serve additional purposes aswell. For example, by depressing the right handlebar grip, thetelescopic movement of the telescoping tube 207D can be manipulated inthe longitudinal direction, including extension (aligned with the thirdrod portion 207C) and contraction (perpendicular to the third rodportion), during operation of the apparatus 190. Similarly, bydepressing the left handlebar grip, the assist assembly 202 can bestored back (e.g., by releasing the main and the secondary ratchetsystems, 221 and 222, respectively) into the bottom cover 212, therebymoving from a working position to a stored position. Alternatively, theassist assembly 202 can be manually operated by hand and/or foot tostore the assist assembly back into the stored position. Also providedon the handlebar 207K are a pair of opposing handles 207M that servedifferent purposes. For example, depression of the right handle adjuststhe telescopic angle (latitudinal motion) of the telescoping tube 207Ddepending upon the position of the apparatus 190 on the stairwell whiledepression of the left handle serves to release the assist assembly 202(e.g., by releasing the main and the secondary ratchet systems, 221 and222, respectively) from the stored position to the working position onthe floor. Typically, the assist assembly 202 will continue to fall onactuation of at least one of the handles 207M (e.g., the left handle)until the assist assembly either contacts the ground, or in thealternative, at least one of the handles (e.g., the left handle) isreleased.

The handlebar 207K further includes various buttons for determining thedirection of movement of the wheelchair to which the apparatus 190 isconnected. In particular, the wheelchair can be manipulated using theapparatus to move up or down a stairway by pressing the appropriatebuttons. For example, by depressing and holding an “up” button 207N, theapparatus 190 can be programmed to move the wheelchair up the stairs bysetting the motorized belts 215 to rotate in a clockwise direction.Similarly, by depressing and holding a “down” button 207O, thewheelchair 192 can be programmed to move downwards on a stairwell bysetting the motorized belts 215 to rotate in a counter clockwisedirection. To ensure safety of the wheelchair occupant, the apparatus190 is equipped with an auto-stop feature. By virtue of the auto-stopfeature, the default mode of the wheelchair to which the apparatus 190is attached is a STOP/HALT mode. Therefore, the wheelchair is capable ofmoving insofar that at least one of the buttons (e.g., Up or DOWN) isdepressed. On releasing the button, the wheelchair automatically comesto a halt. The wheelchair is capable of halting even on a stairway. Thehalting mechanism is achieved by way of a motor brake (not shown) thatis built in the motor assembly 206. In at least some other embodiments,other mechanisms including sensors (e.g., touch sensors) can be used todetect when the handlebar 207 is not being handled (e.g., by not sensinga handler's hand on the handlebar 207K) to automatically trigger theauto-stop mechanism for halting the wheelchair. In alternateembodiments, the handlebar grips 207L and handles 207M can be programmedsuch that holding and rotating one or more of the handles and thehandlebar grips causes acceleration and retardation of the wheelchairgoing up and/or down the stairs while releasing the handles and thehandlebar grips causes the apparatus (and hence, the wheelchair) to cometo a halt. In yet other embodiments, mechanisms other than thosedescribed above can be used to achieve the functionality of thehandlebar 207K described above. Additionally, the handlebar 207K isequipped with a power button 207P that can be used to turn on/off theapparatus 190 thereby preventing the battery from being drained when notin use. Typically, the power button 207P will be illuminated when theapparatus 190 is powered up.

Referring now to FIG. 21, a side perspective view of an exemplaryheadrest assembly 209 is shown in accordance with at least someembodiments of the present invention. The headrest assembly 209 inparticular provides support to the head of the occupant of thewheelchair during ascending/descending the stairwell. As shown, theheadrest assembly 209 includes a headrest bar 209D1, a head support209D2 and an adjustment assembly 209A10. The headrest bar 209D1 inparticular is a narrow, slightly curved bar terminating on the headsupport 209D2 on one end. The other end of the headrest bar 209D1 isconnected to one or more of the smaller connecting rods (see FIG. 10)for attaching the headrest assembly 209 to the respective left and theright frame members 204 and 205 of the apparatus housing.Notwithstanding the fact that the headrest assembly in the presentembodiment is connected to the apparatus housing, it is nevertheless anintention of this invention to include embodiments in which the headrestassembly is connected to the handlebar assembly, or possibly even thedrive mechanism.

Further still, the headrest bar 209D1 has formed thereon a plurality ofnotches 209D10, which can be used to adjust the height of the headrestassembly 209 as desired by virtue of the adjustment assembly 209A10,described below. The head support 209D2 provides a firm yet cushion-likesurface to rest the head during operation of the apparatus 190. In thepresent embodiment, the head support 209D2 includes a foam core 209D3strengthened by a mesh like material (not shown). In alternateembodiments other head supports that are commonly available and/orfrequently used can be used in other embodiments. The shape and size ofthe head support 209D2 can vary to convenience.

The adjustment assembly 209A10 attached at least indirectly to theheadrest bar 209D1, enables adjustment of the height of the head support209D2 while providing additional support to the headrest bar 209D1. Asshown, the adjustment assembly 209A10 includes a compression frame209B1, a CAM lever 209C2 and a support sleeve 209B2 connected togetherin operational association with one another. In particular, thecompression frame 209B1 is a substantially C-shaped structuresurrounding the headrest bar 209D1 and into which the headrest barslides for engaging one of the notches 209D10. The compression frame209B1 also has attached thereto the CAM lever 209C2, actuation of whichreleases the headrest assembly 209 from its stored position allowing theheadrest bar 209D1 to be pulled up to a desired height. The CAM lever209C2 also has mounted thereon, adjacent to the headrest bar 209D1, apair of headrest rotation keys 209A2 held apart from each other by wayof a tension rod 209C1, a pair of compression springs 209C5 andretaining rings 209C4. The rotation keys 209A2 are also secured on thesides facing the CAM lever 209C2 by way of CAM nuts 209C6.

Additionally, each of the rotation keys engage the support sleeve 209B2for rotational movement. The support sleeve 209B2 provides additionalsupport to the CAM lever 209C2 and is frictionally engaged to therotation keys 209A2. As shown, the support sleeve 209B2 is divided intoa central sleeve 209B21 and abutting side portions 209B22 and 209B23respectively. Each of the respective side portions 209B22 and 209B23 arefurther restrained by way of bolts 209A3 and retaining rings 209A4. Awide variety of bolts and retaining rings including for example, HHBolt0.5000 and LW 0.6 can be used. In other embodiments, bolts and retainingrings other than those mentioned above can also be used. In operation,the actuation of the CAM lever 209C2 causes the rotation keys 209A2 torotate thereby pulling the compression frame 209B1 away from theheadrest bar 209D1 and enabling upward movement of the headrest bar.

Notwithstanding the above-described embodiments of FIGS. 1-21, thepresent invention is intended to encompass a variety of otherarrangements of the apparatus 190 and the assemblies thereof. It iscontemplated that the present invention be used for different types ofstairs made of, or covered by a variety of materials including forexample, wood, tile, carpet and possibly even metal. Additionally, thepresent invention can be used for convenient and steady movement over awide variety of surfaces that are difficult to tread in a wheelchairincluding, for example, carpet, wood, stone, tile and metal.

The present invention relates to a variety of embodiments includingadditions and/or refinements to the various features of the apparatusdescribed above, the various assemblies including the body, headrest,assist and the handlebar assemblies and sub-assemblies thereof. Theshape, size, material and orientation of the various features can varyfrom one embodiment to another. For example, although the FIGS. 1-21illustrate an apparatus for use with a wheelchair, it is neverthelesscontemplated that the present invention encompass and includeembodiments enabling the apparatus to be used in conjunction with anupright stretcher or a folding chair for ascending/descending thestairs. Additional safety straps for securing the occupant of thewheelchair can also be provided. The shape, size, type and material ofthe various mechanical components including nuts, bolts, pins and otherfastening means can vary to convenience. Embodiments of the presentinvention can be particularly beneficial insofar as they provide a costeffective, convenient and safe mode of transportation from one point toanother.

Thus, it is seen that a means has been provided by which a standardwheelchair may be modified, or manufactured, with an apparatus that willallow an occupant of the chair, with a handler, to ascend or descend astairway with a minimum of inconvenience or bumps. It is felt that theinvention is of such a nature that it would be affordable by the averagewheelchair occupant and by nursing homes and hospitals to assist inmoving patients from one floor to another on a stairway. Further, thesubject invention will provide means by which handicapped and invalidpatients may be efficiently and safely removed from a multi-storybuilding down a stairway in the event of a fire or other hazard. Thesubject invention may be practiced by a single handler of a wheelchairand occupant on a stairway, if necessary, in an emergency.

Although the present invention is intended to be highly reliable, allphysical systems are susceptible to failure and provision must be madefor such failure. Accordingly, it is understood that safety, in anindustrial process, depends on a wide variety of factors outside of thescope of the present invention including, for example, design of thesystem; installation and maintenance of the components of the system;the cooperation and training of individuals using the system; andconsideration of the failure modes of the other components beingutilized. No representation is made herein that the present invention inits various embodiments will make any use or process safe, and norecommendation is made herein to utilize one preferred embodiment over,or to the exclusion of, another. Rather, the invention results invarious advantages not achieved by prior solutions.

It is specifically intended that the present invention not be limited tothe embodiments and illustrations contained herein, but include modifiedforms of those embodiments including portions of the embodiments andcombinations of elements of different embodiments as come within thescope of the following claims. More generally, while the presentinvention has been shown and described in terms of various embodiments,including at least one preferred embodiment, it is recognized thatequivalents, alternatives, and modifications, aside from those expresslystated, are possible and considered to be within the scope of theappending claims.

We claim:
 1. An apparatus for a wheelchair to assist the wheelchair andan occupant thereof to ascend or descend a stairway, comprising: a trackassembly having a pair of continuous treads, each tread of the pair ofcontinuous treads being rotatably spaced around a freely rotatable wheeland spaced around a motorized wheel that automatically moves the pair ofcontinuous treads around the freely rotatable wheel and the motorizedwheel, the apparatus removably mounted to clamping pins, each clampingpin rigidly secured to at least one frame member of the wheelchair, eachsaid tread positioned with respect to rear wheels of the wheelchair suchthat as the wheelchair is raised or lowered along a stairway having aseries of individual stair steps, the track assembly carrying the weightof the wheelchair along the individual stair steps.
 2. The apparatus ofclaim 1, further comprising an adjustable head rest.
 3. The apparatus ofclaim 1, further comprising an adjustable and pivotable handle bars. 4.An apparatus for assisting a wheelchair and an occupant thereof toascend or descend a stairway or stairway-like structure withoutsubstantial interference with normal operation and/or use of thewheelchair, the apparatus comprising: a housing that is securable to awheelchair; a motorized assembly securable within or substantiallywithin the housing, the assembly for automatically moving the wheelchairup or down the stairway or stairway-like structure; and an attachmentmechanism for securing the housing and the motorized assembly to thewheelchair, thereby preventing the apparatus from separating from thewheelchair.
 5. The apparatus of claim 4, wherein the housing furthercomprises: a frame having two side panels secured to a front and backpanel and having a top panel secured to the two side panels and thefront and back panel; and a pair of notches located within a lowerportion of the side panels, the pair of notches sized to engage pinsfastened to the wheelchair.
 6. The apparatus of claim 4, wherein themotorized assembly is a motorized track assembly rotatably spaced aroundtwo sets of wheels defined as a first set of freely rotatable wheels anda second set of motorized wheels, the second set of motorized wheelsbeing controlled to rotate by a reciprocating motor mechanism, themotorized track assembly further defined by at least one continuoustread having an outer edge that is approximately tangent to a wheel ofthe wheelchair so that the at least one continuous tread can engage aplurality of stair steps or stair step-like structures of the stairwayor stairway-like structure when the wheelchair is raised or loweredalong the stairway or stairway-like structure.
 7. The apparatus of claim4, wherein the motorized assembly includes at least one belt having atleast one continuous tread, the at least one belt spaced around a guidemember defined on the apparatus housing and rotatably mounted to atleast one motorized wheel controlled by a motor assembly for rotatingthe at least one belt around the guide member for moving the wheelchairup and down stair steps or stair step-like structures of the stairway orstairway-like structure.
 8. The apparatus of claim 4, wherein theattachment mechanism further includes a crank handle secured to a barrotatably secured to the front panel of the frame, the bar have a pairof caps secured to each end thereof and each cap, of the pair of caps,includes a U-shaped notch sized to engage a pin fastened to thewheelchair, wherein when the U-shaped notch of the caps are engaged withsaid pin fastened to the wheelchair, the crank handle is moved to rotatethe bar locking each end cap onto said pin preventing the apparatus fromseparating from the wheelchair.
 9. The apparatus of claim 4, furthercomprising a handle-bar assembly that is at least one of adjustable,pivotable, and telescoping.
 10. The apparatus of claim 4, furthercomprising a head-rest assembly that is at least one of adjustable andpivotable.
 11. An apparatus for a wheelchair to assist the wheelchairand an occupant thereof to ascend or descend a stairway or stairway-likestructure, comprising: a frame member; a body assembly having (i) atleast one belt, the at least one belt having at least one continuoustread, the at least one belt rotatably mounted at least indirectly to aguide member that is at least indirectly connected to the frame member,the at least one belt further spaced around at least one motorized wheelthat automatically moves the at least one belt around the guide memberfor carrying a wheelchair with an occupant up and/or down stair steps orstair step-like structures of a stairway or stairway-like structure; and(ii) a drive assembly for controlling the at least one motorized wheelfor rotating the at least one belt.
 12. The apparatus of claim 11,further comprising a head-rest assembly that is at least one ofadjustable and pivotable.
 13. The apparatus of claim 11, furthercomprising a handle-bar assembly, the handle-bar assembly having atleast one tube that is at least one of adjustable and pivotable suchthat the handle-bar assembly is capable of telescopic movement.
 14. Theapparatus of claim 11, further comprising an assist assembly, the assistassembly having (i) at least one wheel; and (ii) at least one supportbar connected at least indirectly to the at least one wheel, the atleast one support bar being capable of pivotal movement to permit theassist assembly to pivot at least with respect to the frame member. 15.The apparatus of claim 11, wherein the drive assembly further comprises:a motor assembly; and a drive axle assembly connected at leastindirectly to the motor assembly.
 16. The apparatus of claim 15, whereinthe motor assembly further comprises: a drive motor; at least onebattery connected at least indirectly to the drive motor for providingpower to the drive motor.
 17. The apparatus of claim 15, wherein thedrive axle assembly further comprises: at least one shaft; and at leastone motorized wheel connected at least indirectly to the at least oneshaft, the motorized wheel capable of being driven by the motorassembly.
 18. An apparatus connected at least indirectly to a wheelchairfor assisting the wheelchair and an occupant thereof to ascend and/ordescend a stairway or a stair-way like structure, the apparatuscomprising: a body assembly having (i) at least one motorized belt formoving a wheelchair up and down the stairway or the stairway-likestructure; and (ii) a drive assembly for controlling the at least onemotorized belt; an assist assembly connected at least indirectly to thebody assembly for providing support to the wheelchair and an occupantthereof; a head-rest assembly connected at least indirectly to the bodyassembly, the head-rest assembly being at least one of adjustable andpivotable; and a handle-bar assembly connected at least indirectly tothe body assembly, the handle-bar assembly at least one of adjustableand pivotable such that the handle bar assembly is capable of telescopicmovement.
 19. The apparatus of claim 18, wherein the drive assemblyfurther comprises: a motor assembly having (i) at least one drive motor;and (ii) at least one battery for providing power to the at least onedrive motor; a drive axle assembly having (i) at least one shaft; and(ii) at least one motorized wheel connected at least indirectly to theat least one shaft and capable of being driven by the at least one drivemotor; a drive chain connected at least indirectly to the motor assemblyand the drive axle assembly for transferring power from the motorassembly to drive the drive axle assembly.
 20. The apparatus of claim19, further comprising a roller assembly connected at least indirectlyto the drive axle assembly, the roller assembly having (i) at least oneshaft; and (ii) at least one wheel for holding the apparatus in anupright stable position.
 21. The apparatus of claim 18, wherein theassist assembly further comprises: at least one shaft for securing theassist assembly at least indirectly to at least one frame member of theapparatus; at least one wheel; and at least one support bar connected tothe at least one shaft and to the at least one wheel, the at least onesupport bar capable of pivoting about the at least one shaft for movingthe assist assembly from a stored position to a working position. 22.The apparatus of claim 18, wherein the head-rest assembly furthercomprises: at least one shaft having a plurality of notches; a headsupport connected at least indirectly to the at least one shaft forproviding support to the head of the occupant of the wheelchair; and anadjustment mechanism for adjusting the height of the at least one shaftby engaging with at least one of the plurality of notches on the atleast one shaft.
 23. The apparatus of claim 18, wherein the handlebarassembly further comprises: at least one frame member; at least one tubemember capable of sliding within the at least one frame member, the atleast one tube member further comprising first, second and thirdportions, the first portion capable of sliding with the second portionand the second portion capable of telescopic movement about the thirdportion; and a handlebar connected at least indirectly to the firstportion for manipulating the body assembly, the assist assembly and thehead-rest assembly, the handlebar having (i) first and second handlegrips; (ii) first and second handle bars; and (iii) a plurality ofbuttons.
 24. The apparatus of claim 18, further comprising an idlershaft assembly, the idler shaft assembly having (i) at least one shaft;and (ii) first and second wheels rotatably mounted at opposing ends ofthe at least one shaft.
 25. The apparatus of claim 18, furthercomprising at least one chair attachment mechanism for connecting theapparatus to the wheelchair, the chair attachment mechanism furthercomprising at least one of a height adjuster mechanism and a widthadjuster mechanism.